<template>
	<view>
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
		<!-- 左侧的滑动区域 -->
		  <scroll-view class="left-scroll-view" scroll-y :style="{ height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
          <view class="left-scroll-view-item" @click="activeChanged(i)" :class="{'active':i === active}">{{item.cat_name}}</view>
        </block>
		   </scroll-view>
		        <!-- 右侧的滚动视图区域 -->
		     <scroll-view :scroll-top="scrollTop" class="right-scroll-view" scroll-y :style="{height: wh + 'px'}">
           <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
             <!-- 二级分类的标题 -->
              <view class="cate-lv2-title">/{{item2.cat_name}}/</view>
              <!-- 三级分类的盒子 -->
              <view class="cate-lv3-list">
                <view class="cate-lv3-item" @click="gotoGoodsList(item3)" v-for="(item3, i3) in item2.children" :key="i3">
                  <!-- 三级分类图片 -->
                  <image :src="item3.cat_icon" mode=""></image>
                  <!-- 三级分类的文本 -->
                  <text>{{item3.cat_name}}</text>
                </view>
              </view>
           </view>
          
		    </scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
        // 当前设备可用的高度
				wh:0, 
        // 分类数据列表
        cateList: [],
        active:0,
        // 二级分类列表
        cateLevel2: [],
        scrollTop:0
			};
		},
    onLoad(){
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods:{
      async getCateList() {
          // 发起请求
          const { data: res } = await uni.$http.get('/api/public/v1/categories')
          // 判断是否获取失败
          if (res.meta.status !== 200) return uni.$showMsg()
          // 转存数据
          this.cateList = res.message
          // 为二级分类赋值 默认是索引为0
          this.cateLevel2 = res.message[0].children
        },
      activeChanged(i){
        this.active = i
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0  ? 1 : 0
      },
      gotoGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    }
	}
</script>

<style lang="scss">
 .scroll-view-container {
   display: flex;
   .left-scroll-view {
     width: 120px;
     .left-scroll-view-item {
       line-height: 60px;
       background-color: #f7f7f7;
       text-align: center;
       font-size: 12px;
       &.active {
         background-color: #ffffff;
         position: relative;
         // 渲染激活项左侧的红色指示边线
         &::before {
           content: ' ';
           display: block;
           width: 3px;
           height: 30px;
           background-color: #c00000;
           position: absolute;
           left: 0;
           top: 50%;
           transform: translateY(-50%);
         }
       }
     }
   }
   .cate-lv2-title {
      font-size: 12px;
      font-weight: bold;
      text-align: center;
      padding: 15px 0;
   }
   .cate-lv3-list {
     display: flex;
     flex-wrap: wrap;
     .cate-lv3-item {
       width: 33.33%;
       display: flex;
       flex-direction: column;
       justify-content: center;
       align-items: center;
       margin-bottom: 10px;
       image {
         width: 60px;
         height: 60px;
       }
       text{
         font-size: 12px;
       }
     }
   }
 }
</style>
